The present invention relates generally to a wireless transmitter for a vehicle and more particularly to a directional garage door opener for a vehicle.
The majority of new homes built are being constructed with garage door openers with remote controllers using RF wireless technology. Many existing homes are also being upgraded with garage door openers using RF wireless technology for accomplishing the remote function. The current trend in the automotive market is to provide new vehicles with factory installed universal garage door opener transmitters. Due to the combined effects of such design variables as the vehicle itself distorting the radiation pattern of a garage door opener transmitter, the Faraday cage surrounding a garage door opener receiver located in a garage, and the low DC power requirements, the operating range between the vehicle garage door opener transmitter and the receiver located in the garage, is extremely limited. In some cases, the range is only 20-30 feet.
Consumers demand ranges approaching several hundred feet so that they can operate the garage door opener several hundred feet from the closed garage door while "on the fly" so that the garage door will be fully open when they arrive at the garage. The several hundred foot range must also exist in all directions. This is desirable for closing the garage door when leaving the garage, especially, when the consumer attempts to close the door when they are at the end of the driveway, or down the street.
Transmitters for garage door openers are designed to have uniform range in all directions to satisfy the previously stated requirements. The tradeoff is to have a higher power transmitter and antenna system that radiates equally in all directions. A higher power transmitter also increases system cost.